Vehicle seat or vehicle cabin having a suspension apparatus and utility vehicle

ABSTRACT

The invention relates to a vehicle seat or to a vehicle cabin having a suspension apparatus comprising a top end part and a bottom end part, which can be deflected relative to the top end part, which are connected to each other in a spring-loaded manner by means of a suspension element, and having a dampening apparatus for dampening vibrations having effect on at least one of the two end parts wherein the dampening apparatus and a distance leveling apparatus for adjusting a distance between the top end part and the bottom end part have an actuator fluid element controlled by common pressure stages.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. 371 andclaims the benefit of PCT Application No. PCT/EP2014/070274 having aninternational filing date of 24 Sep. 2014, which designated the UnitedStates, which PCT application claimed the benefit of German PatentApplication No. 10 2013 110 923.3 filed 1 Oct. 2013, the disclosures ofeach of which are incorporated herein by reference in their entirety.

FIELD

The invention relates to a vehicle seat or vehicle cab, having asuspension device comprising an upper end part and a lower end part thatis deflectable relative to the upper end part, which parts areresiliently interconnected by means of a suspension element, and havinga damping device for damping vibrations acting on at least one of thetwo end parts.

Furthermore, the invention relates to a utility motor vehicle having avehicle seat and having a vehicle cab.

BACKGROUND

Generic vehicle seats or vehicle cabs by means of which the ride comfortin particular of utility motor vehicles can be considerably improved arewell-known from the prior art.

SUMMARY

The object of the present invention is to support generic vehicle seatsor vehicle cabs respectively in a structurally simpler manner relativeto a vehicle body while providing improved seating comfort and ridecomfort respectively.

The object of the invention is solved by a vehicle seat or a vehicle cabhaving the features indicated in claim 1.

The invention is based on the generic prior art in that the dampingdevice and a distance-adjusting device for adjusting a distance betweenthe upper end part and the lower end part comprise a common actuatorfluid element controlled by pressure stages.

Advantageously, at least parts of the damping device and thedistance-adjusting device are implemented in a structurally simplemanner by means of the common actuator fluid element controlled bypressure stages, and therefore these devices can be constructed usingmuch fewer components in conjunction with a fluid-conveying system whichconveys a fluid.

The present distance-adjusting device is a height-adjusting device thatoperates in the vertical direction, and therefore the upper end part canbe displaced relative to the lower end part in a vertical deflectiondirection.

According to the invention, the actuator fluid element controlled bypressure stages is arranged between the two end parts such that it canact on the upper of the two end parts in the vertical direction of thevehicle in both a vibration-isolating manner and a height-regulatingmanner.

As a result, a hydraulically acting damping and height-adjusting unitfor a suspension system, in terms of a damping device together withheight adjustment, and thus the entire substructure of the vehicle seator the vehicle cab respectively can be implemented in an extremelystructurally simple manner, in order to bring about correspondingvibration isolation and/or height adjustment exclusively or in anauxiliary manner.

Therefore, adjustment forces acting in the vertical direction of thevehicle can be generated in a structurally simple manner, as isexplained in the following in greater detail, still by way of example.

In addition, this hydraulically acting damping and height-adjusting unitor the common actuator fluid element controlled by pressure stagesrespectively can produce a linearly rising force characteristic curve orspring characteristic curve respectively over the entirety of theavailable suspension travel.

At this point, it is noted that the common actuator fluid elementcontrolled by pressure stages and the hydraulically acting damping andheight-adjusting unit respectively can be constructed in a structurallysimple manner if the actuator fluid element comprises a hydraulic shockabsorber element.

The vehicle seat according to the invention or the vehicle cab accordingto the invention respectively can be advantageously used in particularin conjunction with utility motor vehicles, since the vehicle driver isbetter protected against premature fatigue owing to the considerablyimproved seating comfort and ride comfort respectively. Furthermore, interms of utility motor vehicles, there is also great interest insolutions for corresponding suspension systems that are structurallysimple and thus less susceptible to faults. This also applies inparticular to agricultural utility motor vehicles.

The suspension device may comprise one or more suspension elements,which may for example be designed as a mechanical suspension elementand/or preferably as a pneumatic suspension element.

The upper end part of the suspension device may for example be attachedto the underside of a seat part of the vehicle seat or to the undersideof the vehicle cab, or may be formed directly from this respectiveunderside.

In this respect, the lower end part of the suspension device may forexample be fastened to a component of a vehicle body or may be formeddirectly by said body.

In any case, the upper end part is mounted on a substructure of thevehicle seat or the vehicle cab respectively relative to the lower endpart such that said upper end part can be deflected relative to thelower end part in the vertical deflection direction, i.e. in thevertical direction of a vehicle, in particular a utility motor vehicle,in particular if external vibrations are acting on the vehicle seat orvehicle cab respectively.

In this respect, the upper end part is a component of the suspensiondevice that vibrates substantially vertically, the main vibrationdirection of which is in the vertical direction of the vehicle, i.e. isvertical.

For this purpose, the suspension device is in particular equipped with avertical suspension element which can act in the vertical direction ofthe vehicle in a resilient manner.

A deflection mechanism for deflecting the upper end part relative to thelower end part can be achieved very simply by means of a scissors typeframe.

In this respect, it is advantageous for the upper end part and the lowerend part to be operatively interconnected by means of a scissors typeframe. As a result, the upper end part is also guided in the verticaldirection in a defined manner.

A preferred variant provides that the actuator fluid element isoperatively connected to a controllable fluid-conveying device, which isin fluid connection with the pressure-stage chamber of the actuatorfluid element such that various height adjustments of the upper end partcan be carried out by controlling the power of the controllablefluid-conveying device. As a result, the fluid-conveying system can beadvantageously further developed.

In particular in this context, it is advantageous for the actuator fluidelement to be operatively connected to a controllable fluid-conveyingdevice which is in fluid connection with the pressure-stage chamber ofthe actuator fluid element such that the fluid can be conveyed out ofthe tension-stage chamber of the actuator fluid element and/or anotherfluid reservoir of the fluid-conveying system into the pressure-stagechamber. As a result, the upper end part can be displaced very preciselyrelative to the lower end part.

A particularly preferred variant provides that the actuator fluidelement is operatively connected to a flow-control valve element, whichis in fluid connection with the actuator fluid element and acontrollable fluid-conveying device such that the power of the pressurestage can be additionally modulated by means of this flow-control valveelement. As a result of this too, the fluid-conveying system can againbe simplified in terms of structure.

Here, the flow-control valve element is a device for modulating a damperperformance at the pressure stage of the actuator fluid element.

Preferably, the flow-control valve element is implemented as anelectrically operable throttle valve, since the flow-control valveelement can be actuated very rapidly by this means, as a result of whichcorresponding pressure changes in the pressure-stage chamber of theflow-control valve element can in turn be achieved very rapidly. It isclear that as an alternative, flow-control valve elements that areoperable in different ways may also be used.

In the present case, vibrations can be very effectively isolated if theflow-control valve element is in fluid connection with the actuatorfluid element and the controllable fluid-conveying device such thatvibrations of one of the end parts can be isolated by means of theflow-control valve element.

The present construction of the fluid-conveying system can be furtherimproved if the flow-control valve element is in fluid connection withthe actuator fluid element and the controllable fluid-conveying devicesuch that the power of the pressure stage can be additionally modulatedby means of this flow-control valve element while not affecting thepower of the fluid-conveying device.

If a low-pressure connection of the fluid-conveying device is in fluidconnection with the tension-stage chamber by means of a low-pressureline and a high-pressure connection of the fluid-conveying device is influid connection with the tension-stage chamber by means of ahigh-pressure line, the low-pressure line and the high-pressure linebeing fluidically interconnected by means of an electrically operableproportional flow control valve, a height adjustment can be carried outin a manner which is particularly simple structurally and in terms ofprocess.

Here, the type and intensity of the control of the common actuator fluidelement controlled by pressure stages can be influenced by means of acontrol algorithm of a corresponding open-loop and/or closed-loopcontrol device.

In this respect, it is advantageous for there to be an open-loop and/orclosed-loop control device for adjusting a fluid-conveying device and/ora flow-control valve element depending on a load acting on the upper endpart.

Specifically, adjusting the fluid-conveying device and/or theflow-control valve element depending on the type and intensity of theexternal forces acting on the actuator fluid element makes it possibleto significantly increase the seating comfort.

The common actuator fluid element controlled by pressure stages mayoperate particularly efficiently if the open-loop and/or closed-loopcontrol device comprises an acceleration-measuring sensor which isarranged on the face of the lower end part and is intended for detectingaccelerations acting on the lower end part.

Yet more precise open-loop or closed-loop control respectively of thecommon actuator fluid element controlled by pressure stages can beachieved if the open-loop and/or closed-loop control device comprises atravel-measuring sensor for detecting a distance and/or a distancevariation between the upper and the lower end part.

The present invention provides an actively controlled suspension systemusing very simple means, which suspension system additionally has thecommon actuator fluid element controlled by pressure stages, which onthe one hand can temporarily adjust a set height level, in particular aset height of a vehicle seat. On the other hand, it can also be activelyinvolved in isolating vibrations. In this respect, this means that thehydraulic damping and height-adjusting unit is also produced to beparticularly simple in structure.

Here, a conventional air suspension element or the like may be used asbasic suspension, while the common actuator fluid element controlled bypressure stages can act in the vertical suspension direction in anauxiliary manner as an additional active component or additional activeassembly.

The controllable fluid-conveying device is preferably in the form of ahigh-pressure pump which is driven by an electric motor and has avariable rotational speed. It has, for example, a defined oil dischargerate in cm³/revolution, which introduces a specific conveyed fluidquantity produced thereby into the pressure-stage chamber orpressure-stage side respectively of the actuator fluid element at acorresponding rotational speed, as a result of which a supporting forceacting on the upper end part is generated in accordance with the flowresistance inherent in the pressure-stage side.

When stopped, i.e. 0.0 l conveying capacity of the controllablefluid-conveying device, the actuator fluid element acts as a passiveshock absorber, which in its basic design contains characteristic datafor the tension-stage and pressure-stage power, as is also used inpassive, commercially available vehicle seats.

When the controllable conveying device is activated, in accordance withits rotational speed, a defined conveyed quantity is transferred fromthe tension-stage side to the pressure-stage side by pumping. The flowresistance produced depending on conveyed quantity at the valve holes inthe pressure stage brings about an extension force or vertically actingsupporting force on the piston-rod side of the actuator fluid elementrespectively. This means that the upper end part of the suspensiondevice to which a load is applied is raised by a value resultingtherefrom.

This active force or extension force respectively is used on the onehand as a control variable for influencing the vibration isolation andon the other hand also to increase the damper performance of theactuator fluid element.

As an additional feature, in the present case the flow-control valveelement is provided, which additionally influences the isolation of theintroduction of vibrations. Here, the damper performance of the actuatorfluid element, which is defined as hard in the passive state, is set tobe softer. This means that the flow resistance between the pressurestage and tension stage of the actuator fluid element is reduced bymeans of the flow-control valve element.

Further advantages, aims and properties of the present invention areexplained with reference to the accompanying drawings and the followingdescription, in which a vehicle seat substructure of a utility motorvehicle seat comprising a common actuator fluid element, controlled bypressure stages, of a damping device and of a distance-adjusting deviceis shown and described by way of example. In the drawings:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of vehicle seat substructurecomprising a common actuator fluid element, controlled by pressurestages, of a damping device and of a distance-adjusting device, theactuator fluid element being arranged between two end parts of asuspension device such that it acts on one of the two end parts in thevertical direction of the vehicle in both a vibration-isolating mannerand a height-adjusting manner,

FIG. 2 schematically shows a fluid circuit diagram of a fluid-conveyingsystem of the actuator fluid element from FIG. 1, and

FIG. 3 schematically shows a graph having different springcharacteristic curves of the suspension device from FIG. 1.

DETAILED DESCRIPTION

The vehicle seat substructure 1, shown in FIG. 1, of a vehicle seat (notshown in greater detail) comprises a suspension device 2, which ischaracterized by an upper end part 3 and a lower end part 4 which, inthis embodiment, are both coupled to one another by a scissors typeframe 5 in a height-adjustable manner.

The scissors type frame 5 substantially consists of two pairs of scissorarms 6 and 7, which in turn each comprise a first scissor arm 8 and 9respectively and a second scissor arm 10 and 11 respectively.

The first scissor arms 8 and 9 respectively are on the one handrotationally mounted on the lower end part 4 by means of a common lowerfixed-bearing device 12. On the other hand, they are mounted on theupper end part 3 in a linearly movable manner by means of a common uppermovable-bearing device 13.

The second scissor arms 10 and 11 behave similarly, and are rotationallymounted on the upper end part 3 by means of a common upper fixed-bearingdevice 14 and are mounted on the lower end part 4 in a linearly movablemanner by means of a common lower movable-bearing device 15.

The first and second scissor arms 8, 10 and 9, 11 respectively of therespective pairs of scissor arms 6 and 7 respectively are rotationallyinterconnected by means of pivotal points 16 (only explicitly providedwith a reference numeral at this point).

Furthermore, the suspension device 2 also comprises a suspension element19, by means of which the two end parts 3 and 4 are resilientlyinterconnected. In this embodiment, the suspension element 19 isprovided by an air suspension element.

When installed, the upper end part 3 is integrated in the vehicle seaton the seat-part side and the lower end part 4 is integrated in thevehicle seat on the vehicle-body side such that the upper end part 3 canrebound and deflect respectively relative to the lower end part 4 in thevertical direction 21 of the vehicle when a corresponding externalstimulus acts on the vehicle seat or on the vehicle respectively.

In order for it to be possible to at least partially isolate thevibrations of the upper end part 3, the vehicle seat substructure 1further comprises a damping device 25 comprising a hydraulic shockabsorber element 26.

The hydraulic shock absorber element 26 is attached by its cylinder part27 to a cross bar 28 of the common lower movable-bearing device 15 andby a piston part 29 (see FIG. 2) to the first scissor arm 9 of thesecond pair of scissor arms 7.

In this embodiment, the hydraulic shock absorber element 26 forms thebasis for the claimed actuator fluid element 31 controlled by pressurestages 30, by means of which element active vibration isolation can alsobe achieved, and furthermore height adjustment of the upper end part 3relative to the lower end part 4 can also be achieved.

For this purpose, the actuator fluid element 31 controlled by pressurestages 30 is arranged between the two end parts 3, 4 such that it canact on the upper end part 3 in the vertical direction 21 of the vehiclein an actively vibration-isolating manner and furthermore in aheight-adjusting manner.

In this respect, the vehicle seat substructure 1 not only comprises asimple damping device 25 but also a distance-adjusting device (notspecifically provided with a reference numeral here) for adjusting thedistance 32 between the upper end part 3 and the lower end part 4, thedamping device 25 and the distance-adjusting device together comprisingthe actuator fluid element 31 controlled by pressure stages 30. Thismeans that the vehicle seat substructure 1 is extremely compact, despiteits functionality being considerably enhanced.

Furthermore, on the one hand, a controllable fluid-conveying device 33for conveying a fluid, this being a hydraulic fluid as in the presentembodiment, and on the other hand a flow-control valve element 34 arealso provided in the vehicle seat substructure 1.

The fluid-conveying device 33 consists of a hydraulic pump 35, which iscontinuously driven by an electric motor 36.

In this case, the flow-control valve element 34 is designed as anelectrically operable throttle valve in the form of a proportional flowcontrol valve 37.

The controllable fluid-conveying device 33, the flow-control valveelement 34 and the actuator fluid element 31 controlled by pressurestages 30 are fluidically interconnected by means of a correspondingfluid pipeline system 38 (only provided with a reference numeral in FIG.1 by way of example), as is described in greater detail in accordancewith the diagram according to FIG. 2, which shows a flow diagram 40 ofthe fluid-conveying system 40A that is configured within the meaning ofthe invention.

In the arrangement according to the flow diagram 40, the actuator fluidelement 31 controlled by pressure stages 30 is arranged on the left. Tothe right thereof, there is the flow-control valve element 34, and thecontrollable fluid-conveying device 33 is arranged further to the right.

The actuator fluid element 31 controlled by pressure stages 30 has anexternal housing 42 which forms a hydraulic-fluid tank 41 and definesthe actual working cylinder 43 in which the piston part 29 consisting ofthe piston head 44 and the piston rod 45 moves.

Some of the hydraulic fluid 46 is stored in the hydraulic-fluid tank 41.Furthermore, the hydraulic-fluid tank 41 also provides a gas-volumecompensation space 47.

The working cylinder 43 comprises a pressure-stage chamber 48, by meansof which the pressure stage 30 of the actuator fluid element 31 isimplemented. The corresponding tension stage 30A is produced inter aliaby means of a pressure-stage chamber 49 of the working cylinder 43.

Furthermore, the actuator fluid element 31 also comprises a rising pipe50 comprising a pressure-compensation valve 51 for pressure compensationwithin the tension-stage chamber 49, in particular when the pressurestage 30 is activated, it then being possible for hydraulic fluid 46 toflow out of the hydraulic-fluid tank 41 into the tension-stage chamber49 through this rising pipe 50.

For pressure compensation in the pressure-stage chamber 48 when thetension stage 30A is activated, a foot valve 52 is provided throughwhich hydraulic fluid 46 can flow out of the hydraulic-fluid tank 41into the pressure-stage chamber 48, but not in the other direction.

Additionally, a pressure-stage/tension-stage valve 53 of the actuatorfluid element 31 is also integrated in the piston head 44, by means ofwhich valve a basic tension stage/pressure stage is inherent in theactuator fluid element 31 as a passively acting hydraulic shock absorberelement.

In addition, as already mentioned above, the actuator fluid element 31is connected, by its cylinder part 27, to the cross bar 28 and thus alsoto the lower end part 4 by means of a lower connecting point 53, whilesaid element is connected, by its piston part 29, to the first scissorarm 9 of the second pair of scissor arms 7 and thus also to the upperend part 3 by means of an upper connecting point 54.

The actuator fluid element 31 comprises, at its tension-stage chamber49, a tension-stage chamber connection 56, with which a low-pressureline 57 is in fluid connection. This low-pressure line 57 represents afluid connection between the tension-stage chamber 49 and a low-pressureconnection 58 of the hydraulic pump 35, and therefore the hydraulicfluid 46 can be conveyed out of the tension-stage chamber 49 by means ofthe controllable fluid-conveying device 33 in the conveying direction 59of the hydraulic pump 35.

A high-pressure line 61 leads from a corresponding high-pressureconnection 60 of the hydraulic pump 35 to a pressure-stage chamberconnection 62, and therefore the hydraulic fluid 46 conveyed out of thetension-stage chamber 49 can be further conveyed into the pressure-stagechamber 48, as a result of which the piston part 29 is accordinglypushed out of the cylinder part 27. As a result, the upper end part 3 israised in the vertical direction 21 of the vehicle and is thus situatedat a greater distance with regard to the lower end part 4.

A connecting line 63 is further connected between the high-pressure line61 and the low-pressure line 57, by means of which connecting line theflow-control valve element 34 is in fluid connection between theactuator fluid element 31 and the controllable fluid-conveying device33. More precisely, the flow-control valve element 34 is connected inparallel with the controllable fluid-conveying device 33 with respect tothe actuator fluid element 31. Therefore, the flow resistance at theactuator fluid element 31 can be changed by means of the flow-controlvalve element 34, as a result of which an influence on thevibration-isolating capacity of the actuator fluid element 31 can beachieved.

An overflow fluid line 64 is further provided between the hydraulic pump35 and the hydraulic-fluid tank 41.

A feed line 65 comprising a non-return valve 66 is arranged between thelow-pressure line 57 and the hydraulic-fluid tank 41. As a result, ifnecessary, hydraulic fluid 46 can be directly conveyed out of thehydraulic-fluid tank 41 into the pressure-stage chamber 48 by means ofthe hydraulic pump 35.

The arrangement shown in the flow diagram 40 represents a firstadvantageous damping and height-adjusting unit 90 of the invention. Inthis respect, this hydraulically acting damping and height-adjustingunit 90 can not only be considered to be an additional functionalassembly of the damping device 25, but at the same time is also theheight-adjusting and distance-adjusting device respectively (notexplicitly provided with a reference numeral here) for adjusting thedistance 32 with respect to the upper end part 3 and the lower end part4 in the vertical direction 21 of the vehicle.

It is also advantageous for a linearly rising force characteristic curve75 to be provided over the entirety of the available suspension travels, as is also shown by the graph 70 shown in FIG. 3.

In the graph 70, the existing suspension travel s is plotted inmillimeters on the abscissa 71, a desired average vertical height level72 being at 90 mm, so that the upper end part 3 can ideally cover bothvertically downwardly available negative suspension travel andvertically upwardly available positive suspension travel of 90 mm ineach case.

The force F counteracting a load on the upper end part 3 is plotted onthe ordinate 73 of the graph 70 in Newtons.

The lower spring characteristic curve 74 plotted on this graph 70 isthat of the suspension element 19 which progresses logarithmically atthe start of the suspension travel s and exponentially at the end of thesuspension travel s; in between, the lower spring characteristic curve74 of the suspension element 19 rises linearly.

The force characteristic curve 75 extending directly above the lowerspring characteristic curve 74 contains the effect of activating theactuator fluid element 31 controlled by pressure stages 30, this forcecharacteristic curve 75 extending both through the point of intersection76 of the line 77 produced by the load of 1000 N and the line 78produced by the vertical height level 72, and also extending completelylinearly over the entirety of the suspension travel s.

The force characteristic curve 75 shows the target values for the forcesgenerated by the damping and height-adjusting unit 90 in the verticaldirection 21 of the vehicle.

The upper force characteristic curve 79 describes the forces generatedby the damping and height-adjusting unit 90 in the vertical direction 21of the vehicle which are above the target values.

It can be clearly seen from the graph 70 that in particular thesuspension element 19 serves as a basis for receiving a basic load whichacts on the suspension as a mass. In the present case, the suspensiondevice 2 is pre-loaded with a load minus half the maximum possiblespring force. The maximum possible spring force is in particularspecified by the dimension of the damping and height-adjusting unit 90,which is 200 N in the vertical direction 21 of the vehicle in the graph70 shown. Therefore, when a load of for example 1000 N is received, thesuspension is supported by a pre-load force of 900 N by means of thesuspension element 19. The desired seat height, which is shown on thegraph 70 as the desired average vertical height level 72 of 90 mm, isnot reached in full yet by means of the suspension element 19. However,the damping and height-adjusting unit 90 or in particular the actuatorfluid element 31 controlled by pressure stages 30 respectively takes onthis difference in distance from the desired average vertical heightlevel 72 of 90 mm. The suspension is therefore brought to this targetheight by means of the force generated by the damping andheight-adjusting unit 90 or in particular by the actuator fluid element31 controlled by pressure stages 30 respectively. In the event oftemporary level variations which may occur for example by the driver'sweight shifting when driving uphill, downhill or at an angle, dependingon the direction and intensity of the variation, the forces generated bythe damping and height-adjusting unit 90 can be increased or decreased.In the present damping and height-adjusting unit 90, the supportingforces generated thereby are utilised to influence externalintroductions of force that are fed into the suspension system. Thedamping and height-adjusting unit 90 may work with the introduction offorce, i.e. a supporting force for carrying the mass is reduced However,it may also work against the introduction of force, the supporting forcebeing accordingly increased.

The type and intensity of the control is taken as a basis in a controlalgorithm of a correspondingly designed open-loop and/or closed-loopcontrol device (not explicitly shown here).

By means of the open-loop and/or closed-loop control device, the dampingand height-adjusting unit 90 may be accordingly adjusted depending on aload acting on the upper end part 3.

For this purpose, the open-loop and/or closed loop control device on theone hand comprises an acceleration-measuring sensor 96 which is arrangedon the face 95 of the lower end part 4 and is intended for detectingaccelerations acting on the lower end part 4 and on the other handcomprises a travel-measuring sensor 97 for detecting the currentdistance 32 and/or a corresponding distance variation between the upperand the lower end part 3, 4.

It will be understood that the embodiment described above is only afirst configuration of the invention. In this respect, the configurationof the invention is not limited to this embodiment.

At this point, reference is explicitly therefore once again made to thefact that the above-described vehicle seat substructure 1 mayalternatively also be used as a vehicle cab substructure, provided thatit is dimensioned accordingly.

All of the features disclosed in the application documents are claimedas being essential to the invention provided that they are novel overthe prior art either individually or in combination.

LIST OF REFERENCE NUMERALS

-   1 vehicle seat substructure-   2 suspension device-   3 upper end part-   4 lower end part-   5 scissors type frame-   6 first pair of scissor arms-   7 second pair of scissor arms-   8 first scissor arm of the first pair of scissor arms-   9 first scissor arm of the second pair of scissor arms-   10 second scissor arm of the first pair of scissor arms-   11 second scissor arm of the second pair of scissor arms-   12 common lower fixed-bearing device-   13 common upper movable-bearing device-   14 common upper fixed-bearing device-   15 common lower movable-bearing device-   16 pivotal points-   19 suspension element-   21 vertical direction of the vehicle-   25 damping device-   26 hydraulic shock absorber element-   27 cylinder part-   28 cross bar-   29 piston part-   30 pressure stage-   30A tension stage-   31 actuator fluid element-   32 distance-   33 fluid-conveying device-   34 flow-control valve element-   35 hydraulic pump-   36 electric motor-   37 proportional flow control valve-   38 fluid pipeline system-   40 flow diagram-   40A fluid-conveying system-   41 hydraulic-fluid tank-   42 external housing-   43 working cylinder-   44 piston head-   45 piston rod-   46 hydraulic fluid-   47 gas-volume compensation space-   48 pressure-stage chamber-   49 tension-stage chamber-   50 rising pipe-   51 pressure-compensation valve-   52 foot valve-   53 pressure-stage/tension-stage valve-   54 lower connecting point-   55 upper connecting point-   56 tension-stage chamber connection-   57 low-pressure line-   58 low-pressure connection-   59 conveying direction-   60 high-pressure connection-   61 high-pressure line-   62 pressure-stage chamber connection-   63 connecting line-   64 overflow fluid line-   65 feed line-   66 non-return valve-   70 graph-   71 abscissa-   72 height level-   73 ordinate-   74 lower spring characteristic curve-   75 force characteristic curve-   76 point of intersection-   77 line produced-   78 further line produced-   79 upper force characteristic curve-   90 damping and height-adjusting unit-   95 face-   96 acceleration-measuring sensor-   97 travel-measuring sensor

What is claimed is:
 1. A vehicle seat or vehicle cab comprising: asuspension device including an upper end part and a lower end part thatis deflectable relative to the upper end part, which parts areresiliently interconnected by means of a suspension element, and havinga damping device for damping vibrations acting on at least one of thetwo end parts, wherein the damping device and a distance-adjustingdevice for adjusting a distance between the upper end part and the lowerend part comprise a common actuator fluid element controlled by pressurestages, and wherein an open-loop and/or closed-loop control device isprovided for adjusting a fluid-conveying device and/or a flow-controlvalve element depending on a load acting on the upper end part.
 2. Thevehicle seat or vehicle cab according to claim 1, wherein the open-loopand/or closed-loop control device comprises an acceleration-measuringsensor which is arranged on the face of the lower end part and isintended for detecting accelerations acting on the lower end part. 3.The vehicle seat or vehicle cab according to claim 1, wherein theopen-loop and/or closed-loop control device comprises a travel-measuringsensor for detecting a distance and/or a distance variation between theupper and the lower end part.
 4. The vehicle seat or vehicle cabaccording to claim 1, wherein the actuator fluid element is operativelyconnected to the fluid-conveying device, which is in fluid connectionwith a pressure-stage chamber of the actuator fluid element such thatvarious height adjustments of the upper end part can be carried out bycontrolling the power of the controllable fluid-conveying device.
 5. Thevehicle seat or vehicle cab according to claim 1, wherein the actuatorfluid element is operatively connected to the fluid-conveying device,which is in fluid connection with a pressure-stage chamber of theactuator fluid element such that the fluid can be conveyed out of atension-stage chamber of the actuator fluid element and/or another fluidreservoir of the fluid-conveying system into the pressure-stage chamber.6. The vehicle seat or vehicle cab according to claim 1, wherein theactuator fluid element is operatively connected to a flow-control valveelement, which is in fluid connection with the actuator fluid elementand the fluid-conveying device such that the power of the pressure stagecan be additionally modulated by means of this flow-control valveelement.
 7. The vehicle seat or vehicle cab according to claim 6,wherein the flow-control valve element is in fluid connection with theactuator fluid element and the controllable fluid-conveying device suchthat vibrations of one of the end parts can be isolated by means of theflow-control valve element.
 8. The vehicle seat or vehicle cab accordingto claim 6, wherein the flow-control valve element is in fluidconnection with the actuator fluid element and the controllablefluid-conveying device such that the power of the pressure stage can beadditionally modulated by means of this flow-control valve element whilenot affecting the power of the fluid-conveying device.
 9. The vehicleseat or vehicle cab according to claim 4, wherein a low-pressureconnection of the fluid-conveying device is in fluid connection with atension-stage chamber by means of a low-pressure line and ahigh-pressure connection of the fluid-conveying device is in fluidconnection with the tension-stage chamber by means of a high-pressureline, the low-pressure line and the high-pressure line being fluidicallyinterconnected by means of an electrically operable proportional flowcontrol valve.